In the past two decades, the research and application of vibration aging stress relief technology have made rapid progress in China. During this period

Through the joint efforts of many domestic units, efforts have been made to improve the vibration aging mechanism, vibration aging process technology, and vibration aging application

We have achieved breakthrough results and formulated the national industry standard for vibration time efficiency in China

The national machinery industry standard JBT5926-2005 has guided the application of this technology and the production of equipment, promoting vibration aging

The widespread application of technology in the mechanical industry.

The key to vibration aging treatment is to eliminate or homogenize residual stresses in metal components, which have an impact on the fatigue of welded components

The impact on lifespan is severe, which has been observed for the past decade. Therefore, as the main purpose of eliminating residual stress

The vibration aging technology can be used to improve the fatigue life of welded components.

A large amount of research data both domestically and internationally indicates that the fundamental role of vibration aging in welded structural components is to "eliminate" residual stresses

Therefore, it is called "vibration stress relief" abroad. The residual stress distribution of welded structural components is extremely uneven, with stress shaving

It is quite large, and a major feature of vibration aging equipment is to reduce high residual stress and homogenize stress distribution. Therefore, vibration

The dynamic aging equipment has a significant effect on "eliminating" residual stresses in welding structures. Meanwhile, due to the "elimination" of residual stress,

Vibration aging can effectively delay the occurrence of fracture cracks and reduce stress corrosion cracking

The revolving arm is the main component on the continuous casting machine. The rotary arm produced by Shanghai Heavy Mining Continuous Casting Technology Engineering Co., Ltd. is mainly

Part of it is a complex plate welded beam, whose structure is shown in Figure 1. There is a high residual welding stress after welding, which causes the workpiece to be welded

Form. In general, in order to meet the size requirements of the drawing during welding, some process plates are added to control the size of the workpiece. After welding, it is necessary to carry out

Stress relief, stress relief

Process board, suitable stress relief process can ensure that the workpiece does not deform, generally stress relief is adopted

Using heat treatment technology, this method is costly and time-consuming. After research, the vibration stress relief process was adopted in this experiment

Prove that removing the process board after vibration meets the size requirements of the workpiece and the effect is good

2、 Vibration aging process experiment

Vibration aging: Based on the structural characteristics of the workpiece, four point support is used, with the excitation point at A and the pickup point at B

Please refer to Figure 1 for the specific location. The vibration aging equipment has good performance and can draw amplitude and frequency simultaneously with vibration aging

Curve, the vibration effect can be observed, as shown in Figure 2

2. Residual stress testing: To observe the effect of vibration aging, 18 blind holes are selected at the main weld seam after vibration aging to relax

The residual stress was tested using the method, and the measurement points are marked in Figure 1. Due to the tight schedule, the vibration aging equipment did not test the residual stress before welding this time

Based on previous data from other units as a reference, the residual stress at the center of the weld seam after welding of this material is measured at around 190MPa with σ 1

Right, this way we can calculate the rate of decrease in the principal stress of the workpiece after vibration. The residual stress results after vibration testing are listed in

3、 Result analysis

1. The vibration aging equipment removes the process board after vibration, and the workpiece does not deform, indicating that the vibration aging effect is good;

The weld seam is relatively complex, and low stress or even compressive stress may occur, as shown in the data of points 17 and 18

Excluding points 3, 6, 17, and 18 in Table 1, take the average value of 94 MPa from point 14 and calculate the workpiece vibration using 190 MPa

After a1, a decrease rate of 51% is a very good effect

4、 Conclusion

In summary, firstly, the vibration aging meets the size requirements of the workpiece, and secondly, the residual stress after vibration is large and the average principal stress is high

The decrease can reach 51%, greatly meeting the requirements of JB/T5926-2005 standard. It is feasible to use vibration aging for workpieces such as rotary arms.